#include "apue.h"
static void sig_usr(int);
int main(void) {
	if (signal(SIGUSR1, sig_usr) == SIG_ERR) {
		err_sys("can not catch sigusr1");
	}
	if (signal(SIGUSR2, sig_usr) == SIG_ERR) {
		err_sys("cann not catch SIGUSR2");
	}
	for(;;) 
		pause();
}

static void sig_usr(int signo) {
	if (signo == SIGUSR1)
		printf("received SIGUSR1\n");
	else if (signo == SIGUSR2)
		printf("received SIGUSR2\n");
	else 
		err_dump("received signal %d\n", signo);
}
